Express News Service
BENGALURU: The growing traffic in space is of serious concern to space scientists globally with launch windows becoming tighter and a challenge. A bigger and more attributing concern of space traffic management (STM) is increasing orbital debris (OD) which is posing a major threat to space launches and robotic missions. OD or space junk is any human-made object in orbit that no longer serves a useful function and includes spent upper stages, retired spacecraft, mission-related debris, fragments etc.
“The low earth orbit (LEO) has the highest concentration of debris. The mass in orbit has increased to 9500 metric tons,” said Chief Scientist for Orbital Debris, National Aeronautics and Space Administration (NASA), Dr Jer Chyi Liou. LEO is an orbit that is relatively close to the earth’s surface. It is a region below 2000 km altitude.
In an exclusive interaction with on the sidelines of the ongoing workshop on space situational awareness (SSA) and space traffic management (STM) by the Indian Space & Research Organisation (ISRO), the NASA chief scientist said that as per the “current estimates of the orbital debris, there are around 27,000 objects measuring 10cm and larger; 500,000 of those measuring one cm and larger and one hundred million of those measuring one mm and larger,” he said.
“The biggest threat is from objects measuring one mm and below because they have the potential to pierce the propellant tanks of the spacecraft. There is no data on the number of such objects in space. The thickness of the propellant tank is approximately 2mm. Because of the pressure the tanks may explode, damage the spacecraft components and adversely impact the mission. A small piece of OD measuring 0.4mm in size can pose a serious threat to astronauts during the spacewalk,” he added. Due to the impact of the speed in space, even sub-mm debris poses a realistic threat to human spaceflight and robotic missions.
Liou said that the problem of OD is getting worse affecting space missions. “We need to comply with the existing best practices on mitigation of OD studied by NASA in 1995, the US government in 2001and the Inter-agency Space Debris Co-ordination Committee (IADC) in 2002 on preserving the near-earth space environment for future generations. Unfortunately, globally, there is low compliance,” he added.
The space scientist warned that “more and more mass in the environment will have a cascading effect. It will lead to accidental collision, which will create more OD and furthermore collisions. It is going to be a serious problem in the future,” cautioned the NASA scientist.
Liou said that two incidents – China’s Anti Satellite (ASAT) test in January, 2007 which used a missile to destroy an old weather satellite and the collision between an inactive Russian communicationssatellite, designated Cosmos 2251, with an active commercial communications satellite operated by US-based Iridium Satellite LLC on February 10, 2009, “had more than doubled the OD” in the environment.“Space is for everyone. We need to balance the benefits (of development) with the environment. Since the launch of Sputnik on October 4, 1957 there have been close to 6000 launches worldwide. We need to manage the side effects of space advancement and technology for safer and sustainable space,” he concluded while lauding ISRO’s contribution to the global community of space scientists in addressing space situational awareness and space traffic management.
BENGALURU: The growing traffic in space is of serious concern to space scientists globally with launch windows becoming tighter and a challenge. A bigger and more attributing concern of space traffic management (STM) is increasing orbital debris (OD) which is posing a major threat to space launches and robotic missions. OD or space junk is any human-made object in orbit that no longer serves a useful function and includes spent upper stages, retired spacecraft, mission-related debris, fragments etc.
“The low earth orbit (LEO) has the highest concentration of debris. The mass in orbit has increased to 9500 metric tons,” said Chief Scientist for Orbital Debris, National Aeronautics and Space Administration (NASA), Dr Jer Chyi Liou. LEO is an orbit that is relatively close to the earth’s surface. It is a region below 2000 km altitude.
In an exclusive interaction with on the sidelines of the ongoing workshop on space situational awareness (SSA) and space traffic management (STM) by the Indian Space & Research Organisation (ISRO), the NASA chief scientist said that as per the “current estimates of the orbital debris, there are around 27,000 objects measuring 10cm and larger; 500,000 of those measuring one cm and larger and one hundred million of those measuring one mm and larger,” he said.
“The biggest threat is from objects measuring one mm and below because they have the potential to pierce the propellant tanks of the spacecraft. There is no data on the number of such objects in space. The thickness of the propellant tank is approximately 2mm. Because of the pressure the tanks may explode, damage the spacecraft components and adversely impact the mission. A small piece of OD measuring 0.4mm in size can pose a serious threat to astronauts during the spacewalk,” he added. Due to the impact of the speed in space, even sub-mm debris poses a realistic threat to human spaceflight and robotic missions.
Liou said that the problem of OD is getting worse affecting space missions. “We need to comply with the existing best practices on mitigation of OD studied by NASA in 1995, the US government in 2001
and the Inter-agency Space Debris Co-ordination Committee (IADC) in 2002 on preserving the near-earth space environment for future generations. Unfortunately, globally, there is low compliance,” he added.
The space scientist warned that “more and more mass in the environment will have a cascading effect. It will lead to accidental collision, which will create more OD and furthermore collisions. It is going to be a serious problem in the future,” cautioned the NASA scientist.
Liou said that two incidents – China’s Anti Satellite (ASAT) test in January, 2007 which used a missile to destroy an old weather satellite and the collision between an inactive Russian communications
satellite, designated Cosmos 2251, with an active commercial communications satellite operated by US-based Iridium Satellite LLC on February 10, 2009, “had more than doubled the OD” in the environment.
“Space is for everyone. We need to balance the benefits (of development) with the environment. Since the launch of Sputnik on October 4, 1957 there have been close to 6000 launches worldwide. We need to manage the side effects of space advancement and technology for safer and sustainable space,” he concluded while lauding ISRO’s contribution to the global community of space scientists in addressing space situational awareness and space traffic management.
